1,161 research outputs found
Weak phase stiffness and mass divergence of superfluid in underdoped cuprates
Despite more than two decades of intensive investigations, the true nature of
high temperature (high-) superconductivity observed in the cuprates
remains elusive to the researchers. In particular, in the so-called
`underdoped' region, the overall behavior of superconductivity deviates
from the standard theoretical description pioneered by Bardeen,
Cooper and Schrieffer (BCS). Recently, the importance of phase fluctuation of
the superconducting order parameter has gained significant support from various
experiments. However, the microscopic mechanism responsible for the
surprisingly soft phase remains one of the most important unsolved puzzles.
Here, opposite to the standard BCS starting point, we propose a simple,
solvable low-energy model in the strong coupling limit, which maps the
superconductivity literally into a well-understood physics of superfluid in a
special dilute bosonic system of local pairs of doped holes. In the
prototypical material (LaSr)CuO, without use of
any free parameter, a -wave superconductivity is obtained for doping above
, below which unexpected incoherent -wave pairs dominate.
Throughout the whole underdoped region, very soft phases are found to originate
from enormous mass enhancement of the pairs. Furthermore, a striking mass
divergence is predicted that dictates the occurrence of the observed quantum
critical point. Our model produces properties of the superfluid in good
agreement with the experiments, and provides new insights into several current
puzzles. Owing to its simplicity, this model offers a paradigm of great value
in answering the long-standing challenges in underdoped cuprates
Robust Sensitivity Analysis for Multi-Attribute Deterministic Hierarchical Value Models
The Air Force\u27s ability to deploy, employ, and sustain operations in forward locations is a key to mission success. An integral part of this strategy is equipment pre-positioning, to include: vehicles, aircraft support, consumable inventory, and munitions. This research focuses on defining and developing a model to aid decision makers with the afloat pre-positioning and deployment of munitions in an effort to ensure that the right weapons are available when, and where needed. This research places a particular focus on the strategic, global pre-positioning of the Afloat Pre-positioning Fleet (APF) in an effort to minimize the overall response time involved with offloading these ships and transporting their cargo to the intended point of use. The model developed in this study is a mixed integer program that was implemented using the General Algebraic Modeling System (GAMS). The model considers the various aspects of pre-positioning (forward operating locations, Standard Air Munitions Packages, and the APF) in order to optimally locate and configure each APF ship. The methodology for this model was tested and verified using precision-guided munitions data for a number of scenarios
Microarray Analysis of Late Response to Boron Toxicity in Barley (Hordeum vulgare L.) Leaves
DNA microarrays, being high-density and high-throughput, allow quantitative analyses of thousands of genes and their expression patterns in parallel. In this study, Barley1 GereChip was used to investigate transcriptome changes associated with boron (B) toxicity in a sensitive barley cultivar (Hordeum vulgare L. cv. Hamidye). Eight-day-old aseptically grown seedlings were subjected to 5 or 10 mM boric acid (B(OH)(3)) treatments for 5 days and expression profiles were determined with DNA microarrays using total RNA from leaf tissues. Among the 22,840 transcripts - each represented with a probe set on the GeneChip - 19,424 probe sets showed intensity values greater than 20(th) percentile in at least one of the hybridizations. Compared to control (10 mu M B(OH)(3)), 5 mM B(OH)(3) treatment resulted in differential expression of 168 genes at least by twofold. Moreover, 10 mM B(OH)(3) treatment resulted in at least twofold induction or reduction in expression of 312 transcripts. Among these genes, 37 and 61 exhibited significantly (P <0.05) altered levels of expression under 5 and 10 mM B(OH)(3) treatments, respectively. Differentially expressed genes were characterized using expression-based clustering and HarvEST:Barley. Investigations of expression profiles revealed that B toxicity results in global changes in the barley transcriptome and networks of signaling or molecular responses. A noticeable feature of response to 8 was that it is highly interconnected with responses to various environmental stresses. Additionally, induction of jasmonic acid related genes was found to be an important late response to B toxicity. Determination of responsive genes will shed light on successive studies aiming to elucidate molecular mechanism of B toxicity or tolerance. To the best of our knowledge, this is the first report on global expression analysis of barley seedlings under B toxicity
ON THE PERFORMANCE OF GNSS LEVELLING OVER STEEP SLOPES
In geodetic applications variety, one of the main current focuses is recently to determine the heights of ground stations with high accuracy. Specially the possibility of acquiring 3D information of the point positioning with high accuracy is opening up new strategies of investigating the heighting. Global Navigation Satellite System (GNSS) for 3D positioning is undergoing rapid developments andGNSS heighting can be an alternative to terrestrial techniques of height measurements. This paper presents a research study on the use of GNSS heighting in the case of steep slopes and multipath issue. Short baseline solution strategieswere performed by using Bernese Software v. 5.0. The analysis results are also compared to the results of techniques of the terrestrial levelling. The results showthat GNSS can be used as an practical surveying method to the terrestrial levelling with comparable accuracies. Furthermore, one can save up to 1 hour using GNSSinstead of geometric levelling over a steep slope of a 100 m. On the other hand, as usual multipath is the primary error source decreasing the efficiency of GNSS, and it has been studied experimentally in this paper
Automated discrimination of psychotropic drugs in mice via computer vision-based analysis
Cataloged from PDF version of article.We developed an inexpensive computer vision-based method utilizing an algorithm which differentiates
drug-induced behavioral alterations. The mice were observed in an open-field arena and their activity
was recorded for 100 min. For each animal the first 50 min of observation were regarded as the drug-free
period. Each animal was exposed to only one drug and they were injected (i.p.) with either amphetamine
or cocaine as the stimulant drugs or morphine or diazepam as the inhibitory agents. The software divided
the arena into virtual grids and calculated the number of visits (sojourn counts) to the grids and instantaneous
speeds within these grids by analyzing video data. These spatial distributions of sojourn counts and
instantaneous speeds were used to construct feature vectors which were fed to the classifier algorithms
for the final step of matching the animals and the drugs. The software decided which of the animals were
drug-treated at a rate of 96%. The algorithm achieved 92% accuracy in sorting the data according to the
increased or decreased activity and then determined which drug was delivered. The method differentiated
the type of psychostimulant or inhibitory drugs with a success ratio of 70% and 80%, respectively.
This method provides a new way to automatically evaluate and classify drug-induced behaviors in mice.
Crown Copyright © 2009 Published by Elsevier B.V. All rights reserved
Inattention and disordered gaming: does culture matter?
Objective: Problematic gaming has emerged as a contemporary concern, leading to the introduction of the diagnostic term 'Internet Gaming Disorder' (IGD; American Psychiatric Association). The present study aims to empirically assess the association between inattention and IGD, in the light of variable levels of vertical-individualism that reflects cultural inclinations towards independence, competitiveness, and hierarchy.
Method: The participants (N=1032) comprised a normative cohort of Massively Multiplayer Online (MMO) gamers (Mage=24 years; 48.7% male). IGD was measured with the nine-item shortform IGD Scale (IGD9-SF), inattention with the Attention Deficit Hyperactivity Disorder (ADHD) Self-Report Scale, and vertical individualism with the Individualism-Collectivism Questionnaire. Complex hierarchical and moderated regressions were employed.
Results: Findings demonstrated an association between IGD and inattention, and additionally showed that this association was exacerbated by a more vertically-individualistic cultural orientation without significant gender differences.
Conclusion: The need of differentially addressing IGD risk among inattentive gamers of diverse cultural orientation is highlighted
Is cyber hygiene a remedy to IPTV infringement? A study of online streaming behaviours and cyber security practices
Spurred by the rapid modernisation of the sector and the advent of Internet Protocol Television (IPTV), audiovisual (AV) piracy is at epidemic levels, with interventions having limited effect. To date, the dominant themes in interventions have been around personal deterrence (i.e. the threat of legal action) and have not considered other factors that may influence an individual’s decision to consume infringing content. In this paper, we consider psychological factors, including perceptions around risk-taking, security behaviours, problematic internet use and personality traits, to gain a comprehensive understanding of factors influencing engagement with IPTV and the potential implications for cyber security. For this purpose, a survey was conducted with 283 participants living in the UK (age range 18–74, male 104), and an integrated structural equation model was constructed. Our findings showed a positive relationship between security behaviours and the perceived risk of viewing IPTV and a negative relationship between the dark personality triad and the perceived risk of viewing IPTV. They suggest that security behaviours fully mediate the relationship between problematic internet use and IPTV risk-taking, indicating a potential new path for anti-piracy interventions with greater efficacy
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User-avatar bond profiles: how do they associate with disordered gaming?
Aims: The avatar constitutes the in-game representation of the gamer. Although aspects of the user-avatar bond (UAB) have been associated with disordered gaming, there is a need for clearer understanding concerning the impact of potential UAB profiles.
Methods: To address this need, the present study recruited a normative sample of 1022 World of Warcraft (WoW) players (Mage = 28.55 years, SD = 9.90). Participants completed the User-Avatar Questionnaire (to assess UAB aspects such as identification, immersion, and compensation), the Proteus-Effect Scale (to assess transference of the avatar's behaviour in real life), and the Internet Gaming Disorder Scale–Short-Form (to assess disordered gaming).
Results: Latent class analysis indicated the existence of three UAB profiles, 'differentiated gamers' (DGs), 'identified gamers' (IGs) and 'fused gamers' (FGs). The DGs were characterized by low scores across all UAB aspects. The IGs did not report significant Proteus Effect (PE) or immersion behaviours, and despite being more identified with their avatar, did not significantly compensate through it. The FGs presented with higher PE, immersion, and compensation, although they did not significantly identify with their avatars, possibly due to having idealized them. Disordered gaming behaviours were significantly lower for the DGs and sequentially higher for the IGs and the FGs. Preoccupation and mood modification behaviours related to gaming disorder were distinctively associated with FGs.
Conclusion: Disordered gaming assessment and treatment implications of the UAB profiles are discussed
Multiple Orbitoides d’Orbigny lineages in the Maastrichtian? Data from the Central Sakarya Basin (Turkey) and Arabian Platform successions (Southeastern Turkey and Oman)
The standard reconstruction of species of Orbitoides d’Orbigny into a single lineage during the late Santonian to the end of the Maastrichtian is based upon morphometric data from Western Europe. An irreversible increase in the size of the embryonic apparatus, and the formation of a greater number of epi-embryonic chamberlets (EPC) with time, is regarded as the main evolutionary trends used in species discrimination. However, data from Maastrichtian Orbitoides assemblages from Central Turkey and the Arabian Platform margin (Southeastern Turkey and Oman) are not consistent with this record. The Maastrichtian Besni Formation of the Arabian Platform margin in Southeastern Turkey yields invariably biconvex specimens, with small, tri- to quadrilocular embryons and a small number of EPC, comparable to late Campanian Orbitoides medius (d’Archiac). The upper Maastrichtian Taraklı Formation from the Sakarya Basin of Central Turkey contains two distinct, yet closely associated forms of Orbitoides, easily differentiated by both external and internal features. Flat to biconcave specimens possess a small, tri- to quadrilocular embryonic apparatus of Orbitoides medius-type and a small number of EPC, whereas biconvex specimens possess a large, predominantly bilocular embryonic apparatus, and were assigned to Orbitoides ex. interc. gruenbachensis Papp–apiculatus Schlumberger based on morphometry. The flat to biconcave specimens belong to a long overlooked species Orbitoides pamiri Meriç, originally described from the late Maastrichtian of the Tauride Mountains in SW Turkey. This species is herein interpreted to be an offshoot from the main Orbitoides lineage during the Maastrichtian, as are forms that we term Orbitoides ‘medius’, since they recall this species, yet are younger than normal occurrence with the accepted morphometrically defined lineage. The consistent correlation between the external and internal test features in O. pamiri implies that the shape of the test is not an ecophenotypic variation, but appears to be biologically controlled. We, therefore, postulate that more than one lineage of Orbitoides exists during the Maastrichtian, with a lineage that includes O. ‘medius’ and O. pamiri displaying retrograde evolutionary features
Sustained postsynaptic kainate receptor activation downregulates AMPA receptor surface expression and induces hippocampal LTD
It is well established that long-term depression (LTD) can be initiated by either NMDA or mGluR activation. Here we report that sustained activation of GluK2 subunit-containing kainate receptors (KARs) leads to α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) endocytosis and induces LTD of AMPARs (KAR-LTD(AMPAR)) in hippocampal neurons. The KAR-evoked loss of surface AMPARs is blocked by the ionotropic KAR inhibitor UBP 310 indicating that KAR-LTD(AMPAR) requires KAR channel activity. Interestingly, however, blockade of PKC or PKA also reduces GluA2 surface expression and occludes the effect of KAR activation. In acute hippocampal slices, kainate application caused a significant loss of GluA2-containing AMPARs from synapses and long-lasting depression of AMPAR excitatory postsynaptic currents in CA1. These data, together with our previously reported KAR-LTP(AMPAR), demonstrate that KARs can bidirectionally regulate synaptic AMPARs and synaptic plasticity via different signaling pathways
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